Thr202Tyr204

Thr202Tyr204 is a mutation designation used in protein variant catalogs to describe substitutions at two positions in a protein sequence: threonine at position 202 and tyrosine at position 204 in the reference sequence. The shorthand indicates that these two residues have been altered in the reported variant, but the exact amino acids replacing Thr at 202 and Tyr at 204 are not specified by the label alone. Full records typically provide the precise substitutions for each position.

Nomenclature and interpretation can vary by database or publication. In some contexts Thr202Tyr204 is used to denote a double-mutant genotype where both indicated positions are altered, whereas in others it may reflect a comparison between a reference sequence and a double-mutated variant. Because the notation does not encode the chosen replacements, clarifying the exact substitutions requires consulting the accompanying sequence description or experimental record.

Functional implications of mutations at positions 202 and 204 depend on the protein context. Threonine and tyrosine are both polar residues, with tyrosine introducing a bulkier aromatic side chain that can affect hydrophobic packing, hydrogen bonding networks, phosphorylation potential, or interactions with ligands and partners. Double substitutions can also perturb local structure, allosteric sites, or active regions, potentially altering stability, activity, or binding properties.

Study of such variants typically involves site-directed mutagenesis to generate the double mutant, expression and purification, and assays assessing activity, stability, and binding. Structural analyses (X-ray crystallography, NMR) or computational modeling may be used to interpret the observed effects and to explore residue-residue interactions within the local region.